The invention relates to a rolling mill train, in particular one for heavy profiled supports or rails, and comprising one or two two-high reversing pre-rolling stands, two reversing universal rolling stands with always one associated edging stand and preferably a universal finishing rolling stand at the end of the train.
This type of rolling mill train for rolling profiled supports (i.e. beams or griders) or rails is already known (in general terms) from DE-PS No. 1 960 601. In this Specification a reversing universal rolling stand for rolling rails is preceded and/or followed by an edging stand which is displaceable transversely to the rolling line. In order to obtain the number of passes necessary for treating in particular the lateral faces of the rail profile or the head and foot faces either preceding edging stand is provided with grooved rolls which are different over the crown length of the roll set (one of which being displaceable for the first pass and the other being displaceable for a subsequent reversing pass), into the rolling line in the axial direction of the rolls. Also the two different pairs of calibers of the edging stand may be arranged in an edging stand which is arranged in front of or behind the reversing universal rolling stand, wherein likewise the grooved rolls of one of the edging stands are displaced into the rolling line for one reversing pass and the grooved rolls of the other are so displaced for a subsequent reversing pass. A disadvantage of such an arrangement is that for two reversing passes in the reversing universal rolling stand the next grooved rolls following over the length of crown of the reduction rolls must be moved into the rolling line for further reduction of the side flanks of the rail profile. In this case accurate insertion of the respective reduction rolls into the rolling line presents particular difficulties. Moreover the new grooved rolls must be effected into the rolling line within the period of time available prior to the next reduction pass. In this case the continuous material throughput may be disadvantageously affected by time delays, or the rolling process may be disadvantageously affected in respect of maintenance of tolerance limits of the profiled rail, or of operational reliability, respectively, owing to inaccurate alignment of the grooved rolls of the edging stand relative to the rolling line.